Hi Mudasir, how do you get to take the derivative of the interpolation of the control voltage sweep? I get what you are doing taking the derivative of the frequency vs Vcntrl but inside virtuoso cadence you cannot take the derivative of that expression since it is a constant, at least in my version i cannot do it. The only thing I can think around is to export the data and take the derivative in another software. I did it just like you
@@MudasirMir7 I meant that the Vcntrl sweep is discrete (i.e 100mV:50mV:1.2V) and the results are a point in the function, and I get that you can build the curve or the function if you tabulate this different steps and then you should be able to o take the derivative of that, but inside the calculator i cannot simply take the derivative of that, i did the exact same as you inside the calculator, but my simulator throws an error stating what I've just explained. My question really is did you move some settings inside the cadence calculator in order to take the derivative of the interpolated curve of those steps or is it just a matter of different versions of the software? Since I can only take the derivative of an expression which results in a curve, not a list of values that represent a curve
I can take for example the derivative of a drain current of a MOSFET doing a DC analysis, but I wouldn't be able to take the derivative of a list of instant current values of that function if I were sweeping the variable of the control voltage on the gate instead of the DC analysis. Since the expression of the calculator is saying to take the derivative of the current that corresponds to a specific control voltage value( which is a constant value, not a function)
Thank you a lot !
perfect
Hi Mudasir, how do you get to take the derivative of the interpolation of the control voltage sweep? I get what you are doing taking the derivative of the frequency vs Vcntrl but inside virtuoso cadence you cannot take the derivative of that expression since it is a constant, at least in my version i cannot do it. The only thing I can think around is to export the data and take the derivative in another software. I did it just like you
The freq is varying with vcntrl and we are measuring the frequency over time so it is not a constant. It would be if Vcntrl is fixed. Hope that helps
@@MudasirMir7 I meant that the Vcntrl sweep is discrete (i.e 100mV:50mV:1.2V) and the results are a point in the function, and I get that you can build the curve or the function if you tabulate this different steps and then you should be able to o take the derivative of that, but inside the calculator i cannot simply take the derivative of that, i did the exact same as you inside the calculator, but my simulator throws an error stating what I've just explained. My question really is did you move some settings inside the cadence calculator in order to take the derivative of the interpolated curve of those steps or is it just a matter of different versions of the software? Since I can only take the derivative of an expression which results in a curve, not a list of values that represent a curve
I can take for example the derivative of a drain current of a MOSFET doing a DC analysis, but I wouldn't be able to take the derivative of a list of instant current values of that function if I were sweeping the variable of the control voltage on the gate instead of the DC analysis. Since the expression of the calculator is saying to take the derivative of the current that corresponds to a specific control voltage value( which is a constant value, not a function)